Dependencies: don't override get_available_name (Django Storages)

The fuction `get_available_overwrite_name` was removed.
There is a setting `file_overwrite` which is set to `True` by default and our
override shouldn't be required anymore.

https://django-storages.readthedocs.io/en/latest/backends/amazon-S3.html#settings

Related: #11502

Author: humitos

readthedocs/builds/storage.py

@@ -8,7 +8,6 @@
 )
 from django.core.exceptions import SuspiciousFileOperation
 from django.core.files.storage import FileSystemStorage
-from storages.utils import get_available_overwrite_name
 
 from readthedocs.core.utils.filesystem import safe_open
 from readthedocs.storage.rclone import RCloneLocal
@@ -47,16 +46,6 @@ def _dirpath(path):
 
         return path
 
-    def get_available_name(self, name, max_length=None):
-        """
-        Overrides Django's storage to always return the passed name (overwrite).
-
-        By default, Django will not overwrite files even if the same name is specified.
-        This changes that functionality so that the default is to use the same name and overwrite
-        rather than modify the path to not clobber files.
-        """
-        return get_available_overwrite_name(name, max_length=max_length)
-
     def delete_directory(self, path):
         """
         Delete all files under a certain path from storage.